1. Technical Field of the Invention
The present invention relates to a manufacturing apparatus for optical fiber wiring boards.
The present specification is based on a Japanese patent application (Japanese Patent Application No HEI 11-171671), and the contents of this Japanese Patent Application are incorporated by reference as a part of the present specification.
2. Background Art
Optical fiber wiring boards collect wiring groups of optical fibers optically connecting a plurality of optical parts, as wiring parts, and in electrical circuit terms, correspond to printed wiring boards which are employed in electrical circuit wiring, or to backplanes, which are used to conduct wiring between boards or between apparatuses. Methods which are known as manufacturing methods for optical fiber wiring boards include methods in which the optical fibers are coated with an adhesive and are then pressure applied to the surface of a substrate to form the wiring.
Japanese Patent No. 2,735,464 (U.S. Pat. No. 5,259,051) discloses, with respect to the manufacture of optical wiring boards (termed backplanes) which optically connect boards on which optical parts are mounted, an optical fiber interconnection apparatus and method in which xe2x80x9c[a] rotatable wheel is mounted on a free end of a manipulatorxe2x80x9d and xe2x80x9ca peripheral portion of the rotatable wheel causes one end of the optical fibers to adhere to the adhesive coated surface of the substrate.xe2x80x9d
Japanese Patent Application, First Publication No. HEI 7-181356 (U.S. Pat. No. 5,421,930) discloses an apparatus in which, in order to automatically wire optical fibers (pigtails) extending from optical devices onto a substrate, the stored optical fibers are wired onto an adhesive sheet by a rotatable wheel, termed a wiring wheel.
Japanese Patent Application No. HEI 9-281645 discloses, with respect to the structure of an optical wiring boards, a through hole which is provided in the lead end of a wiring head which bends an inserted optical fiber and, employing this stress, presses the optical fiber against an adhesive sheet and thus wires it.
In optical wiring boards, configurations are rare in which the wiring pattern of the optical fibers consists of parallel straight lines, and it is necessary to be able to conduct the wiring of free patterns in which the optical fibers bend and cross one another. Furthermore, it is necessary that the terminals of the optical fiber wiring boards have an arrangement which allows for multiconductors of optical part connectors so as to permit the direct connection of optical parts, in concert with an increase in integration, so that a wiring technique which accurately lines up optical fibers at a narrow pitch is extremely important.
The rotatable wheel, wiring wheel, and through hole described above are extremely important parts for the wiring of optical fibers on adhesive sheets, and these structures control the precision of the pattern and the degree of attachment to the substrate of the wiring.
The rotatable wheel of Japanese Patent No. 2,735,464 and the wiring wheel of Japanese Patent Application, First Publication No. HEI 7-181356 also have a structure in which a groove for supporting the optical fiber at a predetermined position is provided in the outer circumference of the rotatable wheel (wiring wheel). For this reason, in the wiring of a pattern having curved portions, when the rotatable wheel faces in the direction in which the pattern is proceeding, the optical fiber which is wired is compressed by the edge of the groove and becomes disordered, so that the optical fiber which has been caused to adhere to the substrate is likely to detach therefrom. This tendency becomes more pronounced as the radius of the curvature in the wiring pattern becomes smaller, or as the diameter of the rotatable wheel becomes larger.
In response to this, it is necessary that the radius of the rotatable wheel be set so as to be larger than the breakage curvature radius of the optical fiber which is wired (the breakage curvature radius of a commonly available single mode optical fiber core is approximately 2 mm), so that the optical fiber is not broken. Furthermore, in order to miniaturize the rotatable wheel, it is also necessary to miniaturize the bearing of the rotatable wheel which permits smooth rotation, and structurally, there Is a limit to such miniaturization.
Furthermore, in Japanese Patent No. 2,735,464, xe2x80x9cas the manipulator moves, the rotatable wheel rotates as a result of friction, and by means of this, tension is exerted on the optical fiber, and by means of this, optical fiber is supplied from the reel on which the optical fiber is wound to the rotatable wheel, and is wired on the substrate,xe2x80x9d so that in order to wire the optical fiber in the manner of the wiring pattern it is necessary to rotate the rotatable wheel by means of friction and to draw exactly that length of optical fiber provided for in the pattern from the reel. However, in actuality, it is extremely difficult to rotate the rotatable wheel in such a manner as to draw only that length of optical fiber provided for in the pattern.
That is to say, when an optical fiber is wired in such a manner as to cross over a previously wired optical fiber, as a result of friction with the previously wired optical fiber when passing over this fiber, the rotatable wheel rotates; at such times, it is thought that sufficient friction cannot be obtained. Furthermore, when wiring is conducted while curving and passing over an optical fiber, a force acts in a transverse direction with respect to the direction of progression, slippage is produced with the lower-side optical fiber, and there is a danger that sufficient friction will not be obtained.
Furthermore, in methods employing a rotatable wheel, the optical fiber is supplied and wired by placing tension on the optical fiber between the rotatable wheel and the reel, so that when sufficient friction cannot be obtained as described above, sufficient tension cannot be obtained, and this makes it impossible to rotate the rotatable wheel in such a manner as to feed only that length of optical fiber which is provided for in the pattern. As a result, this presents a drawback, as it is impossible to achieve the wiring of the pattern.
In conventional wiring methods which employ rotatable wheels in this manner, a number of drawbacks are present, such as the fact that a previously wired optical fiber pattern may become disordered as a result of the rotatable wheel at portions of the wiring pattern which are curved, the precision of the curving pattern cannot be improved as a result of limitations in the miniaturization of the rotatable wheel, and the fact that wiring cannot be conducted as provided for in the pattern when the pattern is such that wiring must conducted over previously wired optical fibers. These present problems when the length of the optical fibers must be made standard or when internal board wiring requires an extremely detailed pattern.
On the other hand, the through hole disclosed in Japanese Patent Application No. HEI 9-281645, which adopts a wiring head mechanism and does not employ a rotatable wheel, does have a simple mechanism; however, because the optical fiber inserted into the through hole is bent at the edge portion of the through hole, the central axis of the through hole and the position at which the optical fiber is applied to the substrate are not in agreement, and the optical fiber is wired at a position which is displaced by a corresponding amount from the track of the wiring head. In the same way as the conventional technology described above, this problem is magnified in the case of so-called multiple wiring, in which the wiring of the pattern employs curves or in which wiring must be conducted over previously wired optical fibers. A method has been considered as a countermeasure to this problem in which the displacement is anticipated in advance and the movement of the wiring head is corrected; however, the mechanism becomes complex, and furthermore, in cases in which the distance between the central axis of the hole and the position at which the optical fiber is applied to the substrate change at points of intersection in the wiring, it is necessary to conduct further complex correction.
In this way, the problems in the wiring apparatus for optical fibers onto optical wiring boards and in the optical fiber wiring method interfere not only with improvements in wiring accuracy but also with the automation of the continuous wiring operation and with an increase in throughput by increasing wiring speed; these problems are not sufficiently considered by the prior art.
It is an object of the present invention to provide an optical fiber wiring apparatus and an optical fiber wiring method which solve the problems described above and serve to conduct automated wiring in which the movement of the wiring mechanism is accurately followed and multiple wiring is possible.
In order to attain the above object, the optical fiber wiring apparatus of the present invention is provided with a wiring substrate on which the optical fibers are wired; a wiring head which guides the optical fibers to the lead end thereof and forms an optical fiber path; an optical fiber feed mechanism which feeds the optical fiber during the wiring operation into the optical fiber path of the wiring head; an optical fiber contact mechanism, which brings the optical fiber, which has been guided to the lead end of the wiring head via the optical fiber path, and the wiring substrate into contact: an XY movement mechanism, which moves the wiring substrate and the wiring head relative to one anther in the X and Y directions in the state in which the optical fiber at the lead end of the wiring head has been placed in contact with the wiring substrate by the optical fiber contact mechanism; and an optical fiber affixing mechanism, which successively affixes, to the wiring substrate, the optical fiber which has been brought into contact with the wiring substrate during movement by XY movement mechanism.
In the optical fiber wiring apparatus having this structure, by means of the optical fiber feed mechanism, the optical fiber is fed into the optical fiber path of the wiring head, and by means of the optical fiber contact mechanism, the wiring substrate and optical fiber guided to the lead end of the wiring head are brought into contact. Furthermore, in this state, the wiring substrate and the wiring head are moved relative to one another in the XY directions by the XY movement mechanism, and furthermore, when movement is conducted by the XY movement mechanism, the optical fiber brought into contact with the wiring substrate is successively affixed to the wiring substrate by the optical fiber affixing mechanism.
By means of this, the movement of the wiring head is accurately followed, and multiple wiring becomes possible.
Furthermore, the optical fiber wiring apparatus of the present invention is a optical fiber wiring apparatus which lays optical fiber down on a wiring substrate; which is provided with a manipulator which is disposed in a plane which is approximately parallel to the surface of the wiring substrate in a movable manner, and which conducts the laying operation of the optical fibers on the wiring substrate, and which manipulator is further provided with: a fiber feed mechanism for feeding optical fibers, a wiring mechanism for wiring, onto the wiring substrate, optical fibers fed by the optical fiber feed mechanism; a Z axial rotation mechanism which rotates about an axis approximately perpendicular to the surface of the wiring substrate and thereby changes the orientation of the wiring of the wiring mechanism; and an optical fiber cutting mechanism which cuts optical fiber fed by the optical fiber feed mechanism.
In an optical fiber wiring apparatus having this structure, while the optical fiber fed by the optical fiber feed mechanism is been wired onto the wiring substrate by the wiring mechanism, the wiring mechanism is moved by the manipulator, and furthermore, the orientation of the wiring of the wiring mechanism is changed by the Z axial rotation mechanism, and thereby, the optical fiber is wired along the pattern.
Then, when wiring is completed, the optical fiber is cut to the length necessary for the wiring by the optical fiber cutting mechanism, and by wiring the entirety of this optical fiber along the pattern, the wiring of the optical fiber is completed, and the wiring operation either terminates, or the wiring of a new optical fiber is conducted in the same manner.
In this way, the optical fiber wiring apparatus is provided with an optical fiber feed mechanism and an optical fiber cutting mechanism, a Z axial rotation mechanism, and a wiring mechanism, so that it is possible to automate a series of processes of the optical fiber wiring.
An optical fiber cutting mechanism is not disclosed in Japanese Patent No. 2,735,464, in Japanese Patent Application, First Publication No. HEI 7-181356, or Japanese Patent Application 9-281645, so that, although patterns in which there is only one starting point/ending point group may be wired, it is impossible to automate wiring operations for patterns having a plurality of such groups.
Furthermore, the optical fiber wiring method of the present invention is a wiring method which conducts the wiring of an optical fiber onto a wiring substrate, wherein the feeding of this optical fiber is adjusted by an optical fiber feed mechanism so that the tension on the optical fiber is within a fixed range, the optical fiber fed by the optical fiber feed mechanism is wired onto the wiring substrate by a wiring mechanism, and the optical fiber is cut to the length required for the wiring by the optical fiber cutting mechanism.
A mechanism for adjusting the tension on the optical fiber by an optical fiber feed mechanism is not disclosed in Japanese Patent No. 2,735,464, Japanese Patent Application, First Publication No. HEI 7-181356, or Japanese Patent Application No. HEI 9-281645, and it is thus impossible to avoid fluctuations in the tension placed on the optical fiber resulting from deficiencies and the like in the amount of rotation of the rotatable wheel or fluctuations in the wiring speed, thus leading to disorder in the wiring. Furthermore, an optical fiber cutting mechanism is not disclosed, so that it is impossible to automate the wiring operations of patterns in which wiring and cutting are repeated, that is to say, in which a plurality of wirings take place.
In the optical fiber wiring method of the present invention described above, an optical fiber feeding mechanism and an optical fiber cutting mechanism and a wiring mechanism are incorporated, and thereby, it is possible to control the feeding of the optical fiber and to conduct accurate wiring. Furthermore, it is possible to automate the series of operations in wiring from the initiation of wiring to the cutting of the optical fiber at the termination of wiring.
Furthermore, the optical fiber wiring method of the present invention is an optical fiber wiring method which employs an optical fiber wiring apparatus which is provided with a wiring substrate, a wiring head which applies an optical fiber to the wiring substrate with a predetermined force, and an optical fiber feed mechanism which feeds stocked optical fiber, which apparatus moves the wiring substrate and the wiring head relative to one another in the XY directions and conducts wiring operations which form a desired optical fiber wiring pattern on the wiring substrate; wherein
an optical fiber of predetermined length is fed by the optical fiber feeding mechanism, in a manner unrelated to the wiring, either before or after the wiring operation or both before and after the wiring operation, and
an optical wiring board having optical fibers of a predetermined length connected to the wiring pattern either before or after the wiring pattern by means of the wiring operation or both before and after said wiring pattern.
One type of optical wiring board is an optical wiring board of a type in which, at the outer side of the wiring board, end parts of optical fibers forming the wiring pattern are provided in such a manner as to extend for a predetermined length. Manufacturing methods for optical wiring boards having this type of special form are nowhere disclosed in the conventional technology described above.
In accordance with the optical fiber wiring method of the present invention, it is possible to cause the parts which form the ends of the wiring pattern in the optical fibers to project to the sides of the wiring substrate by a predetermined length, and it is thus possible to produce optical wiring substrates in which the end parts of optical fibers project by a predetermined length to the sides of the wiring substrate.
Here, as described above, after one wiring pattern has been wired by the optical fiber wiring apparatus, another wiring pattern is wired in a continuous fashion, and either parallel with the wiring operation or after the termination of the wiring operation, the optical fibers mounted between wiring patterns are cut, and thereby, it is possible to wire a plurality of wiring patterns so that the end parts project to the outside of the wiring substrate.
Furthermore, the optical fiber wiring method of the present invention is an optical fiber wiring method which employs an optical fiber wiring apparatus which is provided with a wiring substrate, a wiring head which is provided with an optical fiber path which guides an optical fiber to the lead end thereof and which applies the optical fiber guided to the lead end to the wiring substrate with a predetermined force, and an optical fiber feeding mechanism which feeds stocked optical fiber, which apparatus moves the wiring substrate and the wiring head relative to one another in the XY directions and conducts a wiring operation which forms a predetermined optical fiber wiring pattern on the wiring substrate; wherein, at the initiation of wiring, the wiring head is moved to a wiring initiation position, and in the state in which the optical fiber has been guided to the lead end of the wiring head, this is pressed against the wiring substrate, the wiring head is moved along the wiring pattern with respect to the wiring substrate, the required optical fiber is fed into the optical fiber path of the wiring head by the optical fiber feeding mechanism, and wiring is conducted.
In an optical fiber wiring method structured in this manner, the optical fiber is fed into the optical fiber path of the wiring head by the optical fiber feeding mechanism, and the optical fiber guided to the lead end of the wiring head is pressed against the wiring substrate by the wiring head, and the wiring substrate and the wiring head are moved relative to one another in the XY directions. Furthermore, the required optical fiber is fed into the optical fiber path of the wiring head by the optical fiber feeding mechanism.
By means of this, multiple wiring which accurately follows the movement of the wiring head becomes possible.
Furthermore, the optical fiber wiring method of the present invention is an optical fiber wiring method in which an optical fiber is laid on a wiring substrate by a wiring head, at least a lead end of which is formed with a spherical surface, which has formed in a side surface part thereof a guide groove which guides an optical fiber to the spherical surface part, and which has a pressure groove which extends from the guide groove to the top part of the spherical surface part; wherein, at the initiation of wiring, the wiring head is moved to a wiring initiation position, an optical fiber is fitted into the pressure groove and is pressed against the wiring substrate, the wiring head is moved along the wiring pattern with respect to the wiring substrate, and wiring is conducted.
In the optical fiber wiring operation, in order to automate the wiring of multiple patterns in which wiring and cutting are repeated, that is to say, the wiring of a plurality of wiring patterns which are not continuous, it is necessary to employ a method in which the end part of an optical fiber is automatically installed in the pressure groove of the wiring head at the initiation of wiring; however, this is not found in Japanese Patent No. 2,735,464, Japanese Patent Application, First Publication No. HEI 7-181356, or Japanese Patent Application No. 9-281645.
In accordance with optical fiber wiring method described above, by advancing the manipulator in a state in which the lead end of an optical fiber is pressed onto the wiring substrate, it is possible to fit the lead end of the optical fiber into the pressure groove of the wiring head and thus install it, and it is possible to automatically initiate wiring from a freely selected position on the wiring substrate.